How can I get my civil rights back?

In 1996, I pleaded guilty to a Class E felony for Obstruction of Tax Procedures in a plea bargain with the IRS for gambling on sporting events. They dropped income tax evasion but insisted on a felony. I was told I would lose my civil rights only while on probation and then they would be restored, which they were. I have voted in every election since 2000. I have served on jury duty 3 times. I have bought weapons after filling out the federal forms on multiple occasions. But I tried to buy an AR-15 in December, 2012 and was denied. Then ATF forced me to surrender the weapons I was allowed to have going back to 2000 when my rights were restored. All this over not having a federal wagering permit and not paying one month's excise tax. Incidentally, Judge Roll (killed when Gabby was shot) imposed zero ($0) fine; zero community service; and zero jail time just 3 years low-risk supervision. I was only required to file a tax return each year while on probation. When I finished the three years, I filed a paper to get my rights restored and assumed everything was back to normal until ATF came up with this "prohibited possessor" charge in December. It seems inconceivable to me that I would lose my 2nd Amendment rights for a few football bets and not signing up to pay unconstitutional extortion taxes (different rates for different states on the federal excise tax for wagering) and also the double jeopardy because I already had a misdemeanor (first offense) for the same thing in Iowa in 1986 which led to the IRS "tax evasion" charges that were reduced to the Class E felony. Haven't I paid my debt to society and shouldn't I be allowed to vote, serve on jury duty AND own a gun 17 years after the non-violent conviction and not even a speeding ticket since?